feat: add boost module

[jeonghoyeo7]

Description

This PR adds boost module.

closes: #349

Tasks

• Scaffold boost module (define proto messages, define message types, keys, codec, params and etc)
• Implement basic message server logic
• Add CLI transaction commands
• Add keeper test boilerplate (liquidity, farming, other modules)
• Add necessary logics
• Add gRPC queries
• Add CLI query commands
• Add spec docs
• Add Import / Export genesis
• Refactor overall codebase
• Add test cases
• Add CLI integration tests
• Add simulation tests

References

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• Appropriate labels applied
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• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[github-actions]

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